1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device including a step of processing a substrate and to a processing apparatus.
2. Description of the Related Art
In the semiconductor device such as DRAM & CMOS Logics whose higher density is progressed, in order to suppress a gate leakage current in a thinned gate insulating film, or in order to increase a capacitance of a capacitor, a high dielectric constant film (high dielectric insulating film) has been used as an insulating film.
When a high dielectric film is deposited, it is so required that the film can be formed at a low temperature, a surface morphology of the formed film is uniform and flat, step coverage and/or via-filling performance are superior, and also it is so required that fewer impurities are mixed into the film. The high dielectric film is deposited by supplying processing gas into a processing chamber into which a substrate is loaded. However, when the high dielectric film is deposited, a deposit including the high dielectric film is deposited on an inner wall of the processing chamber or a member such as a substrate supporting tool in the processing chamber, thus involving a problem that the adhered deposit is peeled off from the inner wall, etc, of the processing chamber and is fallen on the processing substrate if the worst happens and included in the high dielectric film. Therefore, in order to suppress such an inclusion of the foreign matter, it is necessary to clean the inside of the processing chamber or the member in the processing chamber by removing the deposit by etching, before the film thickness composed of the deposit reaches a specific thickness.
A wet etching method in this case detaching a reaction tube constituting the processing chamber and dipping it in a cleaning liquid, and a dry etching method in this case supplying excited etching gas into the processing chamber, are known as a method of etching the deposit. In recent years, the dry etching method, which does not require detaching of the reaction tube, has become more popular. As the dry etching method, a method of activating fluorine (F) based gas or chlorine (Cl) based gas by plasma and using it as the etching gas, and a method of activating O2 added BCl3 gas by plasma and using it as the etching gas, are already disclosed. (for example, see non-patent documents 1 and 2, and patent documents 1 to 3). Such etching methods using plasma are frequently performed using a single wafer processing apparatus, in order to achieve uniformity of the plasma density distribution and easiness of control by the biasing voltage.    (Non-patent document 1) T. Kitagawa, K. Nakamura, K. Osari, K. Takahashi, K. Ono, M. Oosawa, S. Hasaka, M. Inoue: Jpn. J. Appl. Phys. 45 (10), L297-L300 (2006)    (Non-patent document 2) Tomohiro Kitagawa, Koichi Ono, Masanori Oosawa, Satoru Hasaka and Minoru Inoue: Taiyo Nippon Sanso Technical Reports NO 24 (2005)    (Patent document 1) Japanese Patent Application Laid-open No. 2006-179834    (Patent document 2) Japanese Patent Application Laid-open No. 2006-339523    (Patent document 3) Japanese Patent Application Laid-open No. 2004-146787)